77 Firefox Extensions Linked to Crypto Wallet and Credential Theft

77 Firefox Extensions Linked to Crypto Wallet and Credential Theft
Socket Threat Research identified 77 Firefox extension identities linked to the “Offside Wallet Theft Factory,” with 40 confirmed malicious extensions that steal wallet secrets or credentials and 37 deceptive sports-score shells that appear to support the same publishing pipeline. The campaign impersonates OKX, Rabby Wallet, TronLink, and other Web3 products using Supabase-controlled loaders, Cloudflare Workers, hardcoded C2 infrastructure, and version repurposing across Firefox IDs. #Firefox #Supabase #CloudflareWorkers #RabbyWallet #OKX #TronLink

Keypoints

  • Socket tracked 77 Firefox extension identities tied to a broader campaign it calls “Offside Wallet Theft Factory.”
  • Forty extensions were confirmed malicious, while 37 additional extensions were deceptive sports-score shells linked by shared code, infrastructure, and publishing artifacts.
  • The campaign has operated since at least March 2026 and continued into August, with 18 additional identities found during the investigation.
  • Some extensions impersonated OKX, Rabby Wallet, and TronLink, using remote-controlled Supabase projects to switch between benign and phishing content.
  • Other variants exfiltrated recovery phrases, private keys, serialized keyrings, credentials, and clipboard data through Cloudflare Workers or hardcoded C2 servers.
  • Historical version histories show several Firefox IDs were repurposed from sports-score shells or utility builds into wallet-stealing extensions.
  • Mozilla was notified about live extensions, and the report warns that exposed recovery phrases or private keys should be treated as permanently compromised.

MITRE Techniques

  • [T1176.001] Software Extensions: Browser Extensions – The campaign is delivered through Firefox add-ons that perform phishing, wallet theft, or credential collection (‘Firefox extension identities linked through code reuse’ / ‘malicious Firefox extensions’).
  • [T1204] User Execution – Victims must install and interact with the extension or submit secrets into its interface for compromise (‘When a victim opens the extension’ / ‘requests a recovery phrase or private key’).
  • [T1059.007] Command and Scripting Interpreter: JavaScript – Malicious logic is implemented in extension JavaScript files such as background scripts and popup code (‘byte-identical copies of background.js, popup.js, popup.html’).
  • [T1036.005] Masquerading: Match Legitimate Resource Name or Location – Extensions impersonate legitimate products and use lookalike names, branding, or homoglyphs (‘impersonate OKX, Rabby Wallet, TronLink’ / ‘The name substitutes a zero for the letter “O” in OKX’).
  • [T1056.002] Input Capture: GUI Input Capture – Fake wallet forms capture recovery phrases and private keys entered by users (‘requests a recovery phrase or private key’ / ‘The import workflow requests a recovery phrase or private key’).
  • [T1005] Data from Local System – Modified Rabby builds access locally stored keyring data before it is encrypted (‘capture serialized keyring data’ / ‘before the legitimate encryption and storage logic runs’).
  • [T1115] Clipboard Data – Some extensions collect clipboard contents and exfiltrate them in chunks (‘collect credentials and clipboard contents’ / ‘transmit them through /html/continue.php’).
  • [T1102.001] Web Service: Dead Drop Resolver – Supabase is abused as a remote controller to deliver phishing URLs (‘queries the public_notes table’ / ‘By changing a single Supabase value’).
  • [T1071.001] Application Layer Protocols: Web Protocols – Exfiltration and control traffic use HTTP(S) web requests to Workers, pages.dev, and API endpoints (‘send stolen recovery phrases’ / ‘POST hxxp://77[.]91[.]100[.]175/html/app[.]php’).
  • [T1020] Automated Exfiltration – Stolen secrets are automatically transmitted to attacker infrastructure as soon as they are captured (‘sends them to a hardcoded C2 server’ / ‘transmit it over plain HTTP’).
  • [T1030] Data Transfer Size Limits – Clipboard data is split into numbered chunks for transfer (‘divides the captured content into numbered chunks’).
  • [T1041] Exfiltration Over C2 Channel – Wallet secrets, credentials, and keyrings are sent directly to attacker-controlled infrastructure (‘exfiltrate them through Cloudflare Workers’ / ‘hardcoded HTTP endpoint’).

Indicators of Compromise

  • [Firefox extension IDs ] confirmed malicious and deceptive extensions – [email protected], [email protected], [email protected], [email protected]
  • [SHA-256 hashes ] malicious package fingerprints – 08b7b064fa9a41b06774315d944ffddff705ab727222a0c3bcac64a77553bf2fb, 4d0912d575087dab5f468214a2fd259bc386472a8b2b93b6e2441cde4bd941cb and 2 more hashes
  • [Supabase project URLs ] remote-control infrastructure for phishing loaders – hxxps://vnigkfdwwyphfafficet[.]supabase[.]co, hxxps://vgksucdjccsojzuhckzk[.]supabase[.]co, and other 6 items
  • [Phishing URL ] wallet-phishing landing page loaded by the 0KX WEB3 loader – hxxps://portal-web3-extension-welcome[.]pages[.]dev/home
  • [Cloudflare Workers endpoints ] wallet-secret exfiltration infrastructure – hxxps://dry-bush-5408[.]animalrescueeducationcenter-org[.]workers[.]dev/, hxxps://winter-smoke-a612[.]icy-star-f45c[.]workers[.]dev/, and other 2 items
  • [HTTP C2 server ] credential and clipboard collection backend – 77[.]91[.]100[.]175
  • [Credential collection URLs ] exfiltration endpoints for stolen logins – hxxp://77[.]91[.]100[.]175/html/app[.]php, hxxp://77[.]91[.]100[.]175/html/continue[.]php
  • [Keyring exfiltration endpoints ] Rabby-derived theft infrastructure – hxxp://id[.]gemachriverdale[.]org:9000/hook/ptvve, hxxp://alt[.]e-wl[.]com:9000/hook/alt, and other N items
  • [Request markers and campaign tokens ] shared identifiers in exfiltration traffic – EQOx7EIPZSNi, action=login&ss=EQOx7EIPZSNi&key=login&w1=
  • [API-Sports endpoints ] deceptive sports-score shell functionality – https://v3.football.api-sports.io/fixtures?live=all, v2.nba.api-sports.io and other sports-data endpoints
  • [Hardcoded file/script names ] shared implementation artifacts – quickVaultNote, public_notes, collectMetrics, apropriate


Read more: https://socket.dev/blog/firefox-crypto-wallet-theft